#include "Arduino.h"

void setup() {
  Serial.begin(115200);
  pinMode(4,OUTPUT); //pin4 RED LED
  pinMode(12, OUTPUT); //pin12 BLUE LED
  Serial.println("*** Start Program ***");
}

void loop() {
  digitalWrite(4, HIGH);
  digitalWrite(12,LOW);
  delay(1000);
  digitalWrite(4, LOW);
  digitalWrite(12,HIGH);
  delay(1000);
}